4. One year, there were about 3,000 institutions of higher learning in the U.S.

Question

4. One year, there were about 3,000 institutions of higher learning in the U.S. (including junior colleges and community colleges). As part of a continuing study of higher education, the Carnegie Commission took a simple random sample of 400 of these institutions. The average enrollment in the 400 sample schools was 3,700, and the SD was 6,500. The Commission estimates the average enrollment at all the 3,000 institutions to be around 3,700; they put a give-or-take number of 325 on this estimate. Say whether each of the following statements is true or false, and explain (a) An approximate 68% confidence interval for the average enrollment of all 3,000 institutions runs from 3,375 to 4,025 (b) If a statistician takes a simple random sample of 400 institutions out of 3,000, and goes one SE either way from the average enrollment of the 400 sample schools, there is about a 68% chance that his interval will cover the average enrollment of all 3,000 schools. (c) It is estimated that 68% of the 3,000 institutions of higher learning in the US. enrolled between 3,700 7325 = 3,375 and 3,700 325 = 4,025 students. (d) The normal curve can?t be used to figure confidence levels here at all, because the data don?t follow the normal curve.

Explanation / Answer

A) TRUE AS 68% confidence interval for the average enrollment runs from one standard deviation away from the mean 3700-325=3,375 to 3700-325=4,025

B) False. this interval will include 68% of the data values

c)True

d) The sample size is large enough. Larger than 30. hence we can use normal curve

Related Questions

Navigate

• Browse (All)
• Browse 4
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.